Conversion of hydrocarbons



Patented July 1947 "fooNvaas IoN 2,423,163 a a a OF HYDROCARBON SCharles L. Thomas, Western Springs,

111., assignor to Universal Oil Products Company, Chicago,

. 111., a corporationof Delaware No Drawing. ApplicatlonOctober 31,1944, i

3 Serial No. 561,319 9 Claims. (01. 19 6 j52) This invention relatesparticularly to the conversion of hydrocarbons in the presence of aspecially prepared catalyst.

In a broad aspectjthe present invention relates to a hydrocarbonconversionprocess which comprises subjecting said hydrocarbon toconversion in the presence of a catalyst comprising a mechanical mixtureof a suitable supporting a material and sublimed molybdenum oxide.-

In one specific embodiment, the present invention relates to ahydrocarbon conversion process which comprises subjecting saidhydrocarbon to conversion at a temperature within the range of about'600? to about 1200 F. in the presence of a catalyst comprising amechanical mixture of alumina and sublimed molybdic oxide. 7 I Q Thebroad scope of the present invention contemplates the conversion ofhydrocarbons in the presence of a specially prepared catalyst and theparticular catalytic reactions to, be effected in any given operationwill dependupon the charging stock to the process and the conditions ofoperation employed. The presentinventionis particularly applicable tothe type of process known as hydroforming. In this process gasoline ornaphtha of relatively low anti-knock characteristics is subjected totreatment in the presence of the catalyst at a temperature within therange of about 900 to about 1100 F. and a superatmospheric pressure ofabout 50to about 2000 pounds per square inch or more. .Inthehydroforming process, hydrogen, either from an external source orrecovered from within the process, is supplied to the reaction zone, butthere is no net consumption of hydrogen. and in fact the quantity ofhydrogen produced exceeds the quantity thereof consumed in the process.In this process aromatic hydrocarbons are produced to a considerableextent, The invention also is applicable to the reforming of gasoline ornaphtha under substantially the same conditions but inthe absence ofadded or recycled hydroge a 1 Another process contemplated by thepresent invention is hydrocracking, in which operation an oil boilinabove the range of gasoline is subjected to contact with the catalyst inthe presence of hydrogen at a temperature. within the range of about 800to about 1000? Hand pressures ranging from atmospheric to- '1000 poundsper square inch or more. In this process, there usually is a netconsumption of hydrogen, and the primary desired product is gasoline ofhigh anti-knock characteristics.

and particularly gasoline to remove undesirable impurities andparticularly sulphur. Desulphurence of the catalyst at a temperaturewithin the range of from about 600 to about 700 and, in some cases, ashigh as 750 F., at atmospheric or slightly superatmospheric pressureswhich generally are not in excess of about 50pounds. It is also withinthe scope of the invention to eiiect the refining treatment in thepresence of hydrogen.

The hereinbefore' recited processes are. examples in which the chargingstocks to the process comprise a mixture of hydrocarbons. Thepresentyinvention is also applicable to the treatment of a more selectedcharging stock to eiiect dehydrogenation and/or dehydrocyclizationreactions, For example, pentane may be subjected to treatment in thepresence of the catalyst to effect dehydrogenation thereof into.amylene.

Similarly, hexane may be subjected to conversion in the presence of thecatalyst to form hexylene and/or benzene. Likewise, heptanes, octanes,nonanes, etc., may be similarly subjected to treatment to form thecorresponding olefin and/or aromatic hydrocarbon. In addition,mono-olefinic hydrocarbons may be subjected to treatment in the presenceof the catalyst to form the corresponding di-olefinic hydrocarbons. Thedehydrogenation and/or dehydrocyclization reactions may beefi'ectedgwithin the broad temperature range of about 800 to about 1200F., and, under low pressures which may be subatmospheric, atmospheric ormoderately superatmospherio. generally not in excess of about 50 poundsper square inch. .The particu-w .55 An example of another processcontemplated by the present invention is the refining, of oil lartemperature to be employed in any given operation will depend upon thespecific charging stock to the process and the products desired.

It is understood that, when selecting the particular temperature andpressure to be employed in any given operation, the time of contact mustalso be considered, as well as the activity of the particular catalystbeing used. The activity of the catalyst will depend somewhat on thespecific method of manufacture as will be hereinafter set forth, Inaddition, it is understood that the reactions hereinbefore set forth aretypical of thosecomprised within the scope of the present invention andthat many, if not all, of these reactions may occur to some extent inany partioular operation of the process.

As he'reinbefore set forth, the primary feature of the-present inventionis the usein the con-.

version of hydrocarbons of a specially prepared catalyst comprising amechanical mixture of a suitable supporting material and sublimedmolybdenum oxide. In the ordinary manufacture of catalysts containingmolybdenum oxide, it is the practice to prepare such catalysts fromcornmercially available molybdic oxide (M003). Since this oxide asproduced commercially is a coarse, dense material, it is the customaryprac- 'lybdic oxide.

tice, when forming composite catalyst, to use the molybdic oxide in theform of a solution or to convert it into .another molybdenum compoundand then use the molybdenum compound so prepared in compositing with thesupporting material. It is apparent to those skilled in the art that themanufacture of composite catalysts in this way is an involved andexpensive procedure. I have found that hydrocarbons may be converted inthe presence of a. molybdenum oxide-containing catalysts prepared in asimpl and inexpensive method from sublimed mo- The sublimed molybdicoxide is a very light, fluffy powder that is extremely active. Becauseof the fine particles, the molybdic oxide may be evenly distributed uponthe support merely by mixing the dry powders and pelletting. Toillustrate the difference in the sublimed molybdic oxide and theordinary mo lybdic oxide, the former has an apparent bulk. density of0.138 gram per cc., as compared to an apparent bulk density of 0.795gram per cc. for

the ordinary molybdic oxide.

In accordance with the invention the sublimed molybdic oxide iscomposited by mechanical mix-. ing with a supporting material. Anysuitable porous supporting material may be used, including aluminumoxide, magnesium oxide, activated bentonite clays, activatedmontmorillonite clays, kieselguhr, etc. In preparing the supportingmaterials, some precautions arenecessary to insure that they possess theproper physical and chemical characteristics. For example, when usingalumina, which is the preferred supporting material of the presentinvention, it is essential that it be of the gamma-alumina form and notof the inactive alpha form. The aluminum oxide may be obtained fromnatural oxide minerals, such as bauxite, or from carbonates, such asdawsonite, or it may be prepared by precipitation of aluminum oxide fromsolutions of aluminum salts such as aluminum sulphate, aluminumchloride, etc., and the precipitate subsequently dehydrated by heat.

As hereinbefore set forth, one of the primary advantages of the presentinvention is that the. e M v of-rosinwas added as a lubricant and themixture}was pelletted. The rosin was removed by h catalyst may readilyand cheaply be prepared by mechanically mixing of a commerciallyavailable aluminum oxide, such as grade A Activated Alu mina, in a drypowdered condition with sublimed molybdenum oxide. These mixed powdersmay then be used as the catalyst or preferably asuitable lubricant isadded and the mixture is then pelletted or otherwise formed intogranules.

Any suitable lubricant may be used to facili' tate pelletting of thepowder and may comprise, for example, rosin, graphite,hydrogenatedcoicoanut oil, stearic acid, starch, etc.

However, it is also within the scope of the -invention to manufacturethe composite catalyst by first preparing an alumina gel or hydrousprecipitate by reacting a soluble aluminum salt with ammonium hydroxideor ammonium carbonate, or byreacting aluminum metal with a weak diluteacid to form an aluminum sol, which is coagulated by heat or a smallamount of base, or by forming such a gel by other methods. The aluminagel in a wet or undried state is then intimately mixed with the molybdicoxide, the mixture dried and subsequently formed into desired shapes bypelletting or otherwise.

In general, the molybdic oxide will comprise from about 2 to about 40%of the composite catalyst. The activity of the particular catalyst willdepend on the amount of molybdic oxide and on its specific method ofmanufacture. The best catalysts are obtained when molybdic oxide isvuniformly distributed throughout the support and itis thereforepreferred that the mechanical mixing be eflicient. As hereinbefore setforth,

the powdered sublimed molybdi'c oxide is in a very fine state ofsubdivision and lends itself to ready uniform distribution throughoutthe composite catalyst mass.

The operation of the process is relatively simple and may take any ofthe conventional forms. Fixed bed processes areof the type in which thecatalyst is disposed within tubes or chambers maintained under thedesired temperature and pressure conditions, and the hydrocarbons passedover the catalyst. Fluidized operations comprise passing the hydrocarbonvapors in admixture with the catalyst powders through a reaction zonewith a velocity regulated to obtain hindered settling in the reactionzone. In this type of operation the hydrocarbons pass through thereaction zone at a greater velocity than does the catalyst, theoperation being controlled so that the catalyst may be removed from thelower portion of the reaction zone while the hydrocarbons are removedfrom the upper portion thereof. Another suitable type of operation isthemoving bed process in which the catalyst is passed countercurrently tothe hydrocarbons. Still another type of operation is the suspensoidprocess in which the catalyst and hydrocarbons are admixed to form aslurry and the slurry is passed into the reaction zone.

It is understood that the present invention is not limited to anyparticular process flow and that any "suitable system for effecting thedesired conversion may be employed.

The following example further illustrates the novelty and utility of thepresent invention.

a" Example The'catalyst was prepared by mixing 20 grams of sublimedmolybdenum oxide, having an apparent-bulk density of 0.138gram per cc.,and 20 grams of. powdered grade A Activated Alumina in a pebble mill.After mixing for an hour, 4%

in, all at 9 32 F. aplitha-having, an Engler initial boiling point 01'-.213 F;',.an end boiling point of 283 F., a brominefnumb'er of 0.3, atoluene content of 8.5%

by volume, and an A. S. T. M. octane number of 58 was subjected tohydroforming in the presence -.'ofl,the above catalyst and 3.5 moles ofhydrogen 'per mole of naphtha at a temperature of 960 F.. a pressure of1000 pounds per square inch and a jweighthourly space velocity of one.The space velocity is defined as the weight of naphtha per :hour "perweight of catalyst in the reaction zone. The products obtained are asfollows:

Recoveries in weight per cent of charge:

The analysis of the liquid product boiling between 194 and 248 F. is asfollows:

Refractive index at 20 C 1.4473

Bromine number 5 Wt. per cent of toluene 51.5

The volume per cent of toluene based on the a 2. A hydrocarbonconversion process which comprises subjecting said hydrocarbon toconversion in the presence of a catalyst comprising a mechanical mixtureof gamma alumina and sublimed molybdic oxide.

'3. A hydrocarbon conversion process which comprises subjecting saidlwdrocarbon to conversion at a temperature within the range of about 600to about 1200 1".in the presence of a catalyst comprising a mechanicalmixture of gamma alumina and sublimed molybdic oxide.

4. A hydrocarbon conversion process which comprises subjectinghydrocarbons boiling within the range of gasoline to reforming in thepresence of a catalyst comprising a mechanical mixture of poroussupporting material and sublimed molybdenum oxide.

5. A hydrocarbon conversion process which comprises subjectinghydrocarbons boiling within the range of gasoline to reforming at atemperature within the range of about 900 to about F., in the presenceof hydrogen and a catalyst comprising a mechanical mixture of gammaaluminum oxide and sublimed molybdic oxide.

6. A hydrocarbon conversion process which comprises subiectinghydrocarbons boiling above the range ofgasoline to cracking in thepresence of a catalyst corruirising a mechanical mixture of a poroussupporting material and sublimed molybdenum oxide.

7. A hydrocarbon conversion process which comprises subjectinghydrocarbons boiling above the range of gasoline to cracking at atemperature within the range of about 800 to about 1000" F., in thepresence of hydrogen and a catalyst comprising a mechanical mixture ofgamma aluminum oxide and sublimed molybdic oxide.

8. A hydrocarbon conversion process which comprises subjecting saidhydrocarbon to dehydrogenation in the presence of a catalyst comeprising a mechanical mixture of a porous supporting material andsublimed molybdenum ox de.

9. A hydrocarbon conversion process which comprises subjecting saidhydrocarbon to dehydrogenation at a temperature within the range ofabout 800 to about 1200 F., in the presence of a catalyst comprising amechanical mixture of gamma aluminum oxide and sublimed molybdic oxide.

CHARLES L. THOMAS.

REFERENCES cr'rEn The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

